Fair-housing advocates planned to file a lawsuit early Tuesday against the U.S. Department of Housing and Urban Development and HUD Secretary Ben Carson for suspending an Obama-era rule requiring communities to examine and address barriers to racial integration.

After nearly 50 years of inaction, the rule was seen as a belated effort by HUD to enforce the landmark civil rights legislation of the 1968 Fair Housing Act, which compelled communities to use federal dollars to end segregation in residential neighborhoods.

The 2015 rule, developed over a six-year period, required every community receiving HUD funding to assess local segregation patterns, diagnose the barriers to fair housing and develop a plan to correct them. Most communities were supposed to submit their plans to HUD every five years, beginning in 2016. Communities without HUD-approved plans would no longer receive federal housing dollars.

Carson, who has long criticized federal efforts to desegregate American neighborhoods as “failed socialist experiments,” suspended the rule in January, allowing local and state governments to continue receiving HUD grants without compliance with the full requirements of the Fair Housing Act.

The lawsuit alleges Carson unlawfully suspended the 2015 rule by not providing advanced public notice or opportunity for comment, according to a draft obtained by The Washington Post.

The agency said local jurisdictions must continue to promote fair housing but granted communities until at least 2024 in most cases to do so, according to a three-page notice published in the Federal Register.

HUD said it based its decision on the fact that more than a third of the 49 plans initially submitted to the agency were rejected as incomplete or inconsistent with fair-housing and civil rights requirements.

Fair-housing advocates who helped develop the rule under the Obama administration said that is precisely why the rule is necessary and that nearly all of the rejected plans were soon accepted after HUD officials stepped in to help.

The agency, in its January announcement, said that the process is too burdensome for communities and that too many HUD resources were being devoted to helping them revise their plans. As a result, HUD said, it would discontinue its review of plans and directed communities in the process of revising their plans not to submit them.

The agency said it would use the additional time to streamline the process and provide more technical assistance so that communities stand a better chance of having their plans approved on the first try.

In the meantime, HUD said communities should revert to what they were supposed to have been doing before the 2015 rule and certify that they have conducted an analysis of impediments to fair housing and taken actions to overcome them.

Housing advocates said the retreat would perpetuate housing segregation, given earlier assessments that the previous provisions were essentially toothless.

“HUD has continued to grant federal dollars to municipalities even when they know the municipalities are engaging in discrimination,” said Lisa Rice, president and chief executive of the National Fair Housing Alliance, one of three housing advocacy groups that joined the lawsuit. “They are rewarding cities for bad behavior.”

In 2008, the National Commission on Fair Housing and Equal Opportunity, led by former HUD secretaries Jack Kemp, a Republican, and Henry Cisneros, a Democrat, reported that “HUD requires no evidence that anything is actually being done as a condition of funding.”

In 2009, HUD found that many communities could not produce documentation of their efforts to assess and address fair-housing concerns.

A 2010 report by the Government Accountability Office revealed that nearly a third of jurisdictions had not completed an analysis within five years. Of the ones that had, the GAO found that most were limited to aspirational statements of vague goals without defined time frames.

“HUD required jurisdictions only to certify that, every few years, they analyzed barriers to fair housing in their communities, made gestures in the direction of solving them, and memorialized this analysis in their own files (never reviewed by HUD),” the lawsuit said, according to the draft. “As both HUD and the Government Accountability Office found, putting local jurisdictions on the honor system was ineffective.”

Rice met with Carson last week to ask him to reinstate the rule and enforce it. The Texas Low Income Housing Information Service and Texas Appleseed, two nonprofit organizations that had previously sued HUD over other fair-housing issues, also joined the lawsuit.

A HUD spokesman declined to comment on the lawsuit, pointing to a statement in January when the agency suspended the rule. “The Assessment of Fair Housing tool for local governments wasn’t working well,” the HUD statement said. “HUD stands by the Fair Housing Act’s requirement to affirmatively furthering fair housing, but we must make certain that the tools we provide to our grantees work in the real world.”

The lawsuit also accuses HUD of violating its statutory duty to ensure that federal funds are used to promote fair housing and seeks a court order requiring the agency to immediately restart the rule.

“Decades of experience have shown that, left to their own devices, local jurisdictions will simply pocket federal funds and do little to further fair housing objectives,” the lawsuit said. “Judicial intervention is necessary to vindicate the rule of law and to bring fair housing to communities that have been deprived of it for too long.”

In 2009, a district court found Westchester County in New York could produce no evidence that it had ever evaluated the extent of racial segregation or committed to a plan to redress it.

The county had for years certified it was complying with the Fair Housing Act, even as it deliberately concentrated affordable housing in a small number of predominantly black and Latino communities while distributing millions in HUD grants to overwhelmingly white suburbs that refused to allow affordable housing, according to the complaint against HUD.

After the 2009 court decision, HUD began asking municipalities to submit their analyses of housing patterns. More than a third could not produce one. Of those that did, half were deemed unacceptable. And only a fifth of the jurisdictions that submitted their analyses committed to doing anything within a particular time frame.

The exercise eventually resulted in the 2015 rule requiring communities take meaningful action to overcome long-standing patterns of segregation and analyze housing patterns, concentrated poverty and disparities in access to transportation, jobs and good schools.

Since the rule, housing advocates say, many communities have made great strides. Officials in Paramount, Calif., have set deadlines to amend its zoning ordinance to make housing more inclusive. New Orleans has promised to create 140 affordable rental units in wealthier communities by 2021 and increase homeownership among families receiving housing subsidies by 10 percent each year.

Chester County, Pa., promised to make it easier for low-income families receiving housing vouchers to move to wealthier neighborhoods with better schools and more job opportunities. El Paso County, Colo., has committed to developing 100 subsidized affordable housing units in communities with better opportunities. Philadelphia committed to addressing the problem of widespread evictions in minority neighborhoods.

But many communities continue to struggle to address the impediments to fair housing, advocates say. In Hidalgo County, Tex., which has historically ignored the needs of the predominantly Latino population in “colonias” that often lack basic infrastructure such as water, sewage, electricity and paved roads, officials have no incentive to improve their plan now that HUD no longer requires it.

And advocates worry that Corpus Christi, Tex., will not direct hundreds of millions of dollars in federal disaster relief money after Hurricane Harvey toward fair housing.

“My fear is that HUD’s rescission of the rule tells communities, ‘You’re off the hook,’ ” said Madison Sloan, director of Texas Appleseed’s Disaster Recovery and Fair Housing project. “ ‘We’re going to keep giving you money even while you keep perpetuating segregation.’ ”

Carson, during his January 2017 confirmation hearing, criticized the 2015 rule for compelling communities receiving HUD funding to look around for “anything that looks like discrimination.”

“They’re not responding to people saying there’s a problem,” Carson said. “They’re saying go and look for a problem and then give us a solution. And what I believe to be the case is we have people sitting around their desks in Washington, D.C., deciding on how things should be done, you know, telling mayors and commissioners that you need to build this place right here and you need to put these kinds of people at it.”

Tracy Jan covers the intersection of race and the economy for The Washington Post. She previously was a national political reporter at the Boston Globe.